How to convert joules to calories

How to convert energy in joules (J) to calories (cal).

Small & large calories

Small calorie (cal) is the energy needed to increase 1 gram of water by 1°C at a pressure of 1 atmosphere.

Large calorie (Cal) is the energy needed to increase 1 kg of water by 1°C at a pressure of 1 atmosphere.

Large calorie is also called food calorie and is used as a unit of food energy.

How to convert from joules to calories

Joules to thermochemical calories

1 calth = 4.184 J

The energy in thermochemical calories E(calth) is equal to the energy in joules E(J) divided by 4.184:

E(cal) = E(J) / 4.184

Example

Convert 600 joules to thermochemical calories.

E(cal) = 600J / 4.184 = 143.4 calth

Joules to 15°C calories

1 cal15 = 4.1855 J

The energy in 15°C calories E(cal15) is equal to the energy in joules E(J) divided by 4.1855:

E(cal15) = E(J) / 4.1855

Example

Convert 600 joules to 15°C calories.

E(cal15) = 600J / 4.1855 = 143.352 cal15

Joules to large/food calories

1 Cal = 4.184 kJ = 4184 J

The energy in large/food calories E(Cal) is equal to the energy in joules E(J) divided by 4184:

E(Cal) = E(J) / 4184

Example

Convert 600 joules to food calories.

E(Cal) = 600J / 4184 = 0.1434 Cal

Joules to calories conversion calculator ►